System for electrical stimulation

ABSTRACT

In an embodiment, an electrical stimulation system can include one or more of an electrode assembly including one or more electrodes and an electronics subsystem. In some variations, each of the one or more electrodes can include a hydrophilic layer and a conductive layer. In some variations, the electronics subsystem can include one or more of a control module, power module, and a stimulus generator. In some variations, the electrical stimulation can further include one or more of an electrical attachment system, mechanical attachment system, head apparel assembly, flexible housing, and/or any other suitable component. The electrical stimulation system functions to apply electrical stimulation but can additionally or alternatively function to measure/and or record one or more biosignals from a user.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/468,624 filed 8 Mar. 2017, U.S. Provisional Application No.62/486,348 filed 17 Apr. 2017, U.S. Provisional Application No.62/468,616 filed 8 Mar. 2017, and U.S. Provisional Application No.62/526,643 filed 29 Jun. 2017, each of which is incorporated in itsentirety by this reference. This application is related to U.S.application Ser. No. 14/470,683 filed 27 Aug. 2014, U.S. applicationSer. No. 15/250,070 filed 29 Aug. 2016, U.S. application Ser. No.14/470,747 filed 27 Aug. 2014, U.S. application Ser. No. 15/250,160filed 29 Aug. 2016, U.S. application Ser. No. 15/295,008 filed 17 Oct.2016, and U.S. application Ser. No. 15/657,915 filed 24 Jul. 2017, eachof which is incorporated in its entirety by this reference.

TECHNICAL FIELD

This invention relates generally to the biosignals field, and morespecifically to a new and useful electrode system for electricalstimulation.

BACKGROUND

Electrode systems in the biosignals field are used to transmitelectrical signals to a subject and can be used to detect or measurebiosignals from the subject. Current electrode systems for electricalstimulation and/or biosignal detection are, however, insufficient formany reasons including inadequate contact between the subject and theelectrode(s) of a system, non-robust contact between the subject and theelectrode(s) of a system, inadequate accommodation of individualanatomical variation across subjects, subject discomfort while using anelectrode system, undesirable pivoting due to improper spatialconfiguration of electrodes or improper configuration of electrodecontact forces with respect to the anatomy of the human head and/orindividual anatomical variation, and/or limited use within multipleelectrical simulation or biosignal detection paradigms.

Thus, there is a need in the biosignals field for a new and usefulsystem for electrical stimulation. This invention provides such a newand useful system.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts a schematic of a system for providing electricalstimulation and/or detecting biosignals of a user;

FIG. 2A depicts an assembled view of a variation of a system forproviding electrical stimulation and/or detecting biosignals of a user;

FIGS. 2B-2D depict exploded views of a variation of a system forproviding electrical stimulation and/or detecting biosignals of a user;

FIG. 2E depicts a cross-sectional view of a variation of a system forproviding electrical stimulation and/or detecting biosignals of a user;

FIG. 3 depicts a variation of a set of electrode placement regions on asystem for providing electrical stimulation and/or detecting biosignalsof a user;

FIG. 4A depicts a variation of a cosmetic outer element attached to ahead assembly mechanism;

FIGS. 4B-4C depict exploded views of a variation of a cosmetic outerelement attached to a head assembly mechanism;

FIG. 4D depicts an outer broad surface of a variation of a cosmeticouter element;

FIG. 4E depicts a cross-sectional view of a variation of a cosmeticouter element attached to a head assembly mechanism;

FIG. 5A depicts a view of a variation of a coupler assembly;

FIGS. 5B-5C depict exploded views of a variation of a coupler assembly;

FIG. 6A depicts a cross-sectional view of a variation of a couplerassembly having an attachment system including a set of conductivepolymer contacts;

FIG. 6B depicts a view of a variation of a coupler assembly having anattachment system including a set of conductive polymer contacts;

FIG. 7A depicts a view of a variation of an electrode assembly;

FIG. 7B-7C depict exploded views of a variation of an electrodeassembly;

FIG. 7D depicts a cross-sectional view of an electrode assembly havingan attachment system including a set of conductive polymer contacts;

FIGS. 7E and 7F depict views of an outer broad surface and an innerbroad surface, respectively, of a variation of an electrode assembly;

FIG. 8 depicts a variation of an electrode having a hydrophilic layerincluding a series of protrusions;

FIGS. 9A-9C depict a set of dimensions (D1-D6) and a set of angles(A1-A8) relating a set of electrodes in a variation of a system forproviding electrical stimulation and/or detecting biosignals of a user;

FIG. 10 depicts a variation of a system for providing electricalstimulation and/or detecting biosignals of a user having a head assemblymechanism including a frame wrapped at least partially circumferentiallyaround the head of a user;

FIG. 11 depicts a variation of a system for providing electricalstimulation and/or detecting biosignals of a user having a head assemblymechanism including a set of bands wrapped at least partiallycircumferentially around the head of a user;

FIG. 12 depicts a variation of a system for providing electricalstimulation and/or detecting biosignals of a user having a head assemblymechanism including a glasses frame; and

FIG. 13 depicts a variation of a system for providing electricalstimulation and/or detecting biosignals of a user having a head assemblymechanism including an electrode assembly insertable into a hat.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments of the inventionis not intended to limit the invention to these preferred embodiments,but rather to enable any person skilled in the art to make and use thisinvention.

1. Overview.

As shown in FIG. 1, an embodiment of the system 100 includes: anelectrode assembly 110 including one or more electrodes 112 and acoupler assembly 128 electrically connected to the electrode assembly110. In some variations (e.g., FIGS. 2A-2E), the system 100 can includean electrode housing 120, an electronics subsystem 130, an electronicshousing 144, an attachment system 150, a cosmetic outer element 160, ahead apparel assembly 170, and/or any other suitable component. Thesystem 100 functions as an electrical stimulation device (e.g., toimprove user performance, improve treatment of a user condition, improveuser focus, improve user relaxation, improve user memory, improve usercognition, etc.), and can additionally or alternatively function tomonitor/record biosignals (e.g., electroencephalography (EEG) signals)from a user, or have any other suitable functionality.

2. Benefits.

There are numerous scenarios in which electrical stimulation applied(e.g., transcranially) to a user has been demonstrated to be beneficial.Electrical stimulation can be used for cognitive enhancement/training,such as to improve memory, focus, attention, problem solving, languageabilities, mathematical abilities, etc. The use of electricalstimulation has also been shown to be beneficial for athleticperformance, demonstrating improvements in the flexibility, speed,and/or skill of athletes. Electrical stimulation can also play a role intreating various medical conditions, such as neuropsychiatric conditions(e.g., depression, anxiety, Parkinson's disease, chronic pain, etc.),brain injuries (e.g., stroke), and others.

The wide variety of head shapes and sizes among the potential user base,however, has made it difficult to properly and precisely stimulate oneor more predetermined brain regions among users with a single device.The inventors have discovered that designing the device with a flexibleform factor can help properly and comfortably apply electricalstimulation to a wide variety of users. In some variations, thisflexibility is at least partially obtained by one or more flexibleand/or compliant housings. Additionally or alternatively, thisflexibility can at least partially be achieved through flexibleelectrical interfaces, such as those constructed from one or moreconductive polymers. Further additionally or alternatively, thisflexibility can at least partially be achieved through compliant and/oradjustable electrodes (e.g., pivoting electrodes or electrodes loftedabove a surface using material such as soft foam). This flexibility canalso at least partially be obtained through a vertical alignment of anelectronic attachment system, such that one or more electrodes can flexabout a corresponding vertical axis (e.g., about an electrode rotationalaxis parallel the vertical alignment axis). These variations can providethe benefits not only of user comfort but also a proper location ofelectrical stimulation application.

3. System.

As shown in FIG. 1, the system 100 includes: an electrode assembly 110including one or more electrodes 112 and a coupler assembly electricallyconnected to the electrode assembly 110. In some variations (e.g., FIGS.2A-2E), the system 100 can include an electrode housing 120, anelectronics subsystem 130, an electronics housing 144, an attachmentsystem 150, a cosmetic outer element 160, a head apparel assembly 170,and/or any other suitable component.

The system 100 functions to allow a user to receive electricalstimulation through a headpiece, wherein the electrical stimulation ispreferably applied to predetermined regions of the scalp in order totarget predetermined regions of the brain, but can additionally oralternatively be applied to regions chosen by the user, recommended by aclinician, chosen by an algorithm, randomly chosen, or otherwisedetermined. Additionally or alternatively, the system 100 can functionto facilitate sensing (e.g., biometric sensing) of signals from a userin cooperation with, or in absence of, stimulation. The system 100 canadditionally or alternatively incorporate or cooperate with one or moreof: transducers (e.g., optical sensors, optical emitters, ultrasonictransducers, etc.), additional sensors (e.g., temperature sensors,activity detecting sensors, sensors associated with position, velocity,or acceleration detection, biometric sensors, etc.) for sensing signalsfrom the user, additional sensors (e.g., temperature sensors, barometricpressure sensors, light sensors, microphones, etc.) for sensing signalsfrom the environment of the user, and any other suitable module.

The system 100 can facilitate placement of a set of electrodes on a widevariety of user head morphologies (e.g., head shapes, head sizes, headcontours, etc.), such as a variety of user forehead morphologies. Thiscan be accomplished collectively through a variety of flexible materialsused in the construction of the system 100 and their arrangement withinthe system 100. The system 100 can further facilitate maintenance of anelectrode configuration that provides desired impedance characteristicsand/or a desired type and location of contact at the user-electrodeinterface during placement and/or during use of the system 100. Thesystem 100 can also include features configured to provide a high levelof comfort in terms of wearability, as the user wears the system 100during a period of stimulation treatment.

In some embodiments, the system 100 can be configured to interface withand/or include any of the embodiments, variations, and/or examples ofelectrode systems described in U.S. application Ser. No. 14/878,647entitled “Electrode System for Electrical Stimulation” and filed on 8Oct. 2015 and/or electrode systems described in U.S. application Ser.No. 14/470,683 entitled “Electrode System for Electrical Stimulation”and filed on 27 Aug. 2014, and/or electrode systems described in U.S.application Ser. No. 29/553,732 entitled “Biointerface Electrode” andfiled on 4 Feb. 2016, which are each herein incorporated in its entiretyby this reference; however, the system 100 can alternatively beconfigured to interface with and/or position any other suitable type ofelectrode or functional unit at the head of the user.

The system 100 is preferably configured to be worn by a user who is awayfrom a research or clinical setting, such that the user can wear thesystem 100 while he or she is in a natural setting (e.g., at home, at agym, outdoors, etc.). The system 100 can additionally or alternativelybe configured to be operated by a user who is in a research setting, aclinical setting, or any other suitable setting. Furthermore, while someembodiments of the system are configured to be worn at the head of theuser, alternative embodiments of the system 100 can be configured to beworn or coupled to any other suitable body region of the user.

In some embodiments, the system 100 can implement and/or facilitateimplementation of one or more embodiments, variations, or examples ofthe method(s) described in U.S. application Ser. No. 14/470,747 entitled“Method and System for Providing Electrical Stimulation to a User” andfiled on 27 Aug. 2014 and/or U.S. application Ser. No. 15/059,095entitled “Method and System for Providing Electrical Stimulation to aUser” and filed on 2 Mar. 2016, which are each incorporated in itsentirety by this reference. However, the system can implement anysuitable method of use.

As such, in embodiments and variations, the system 100 can be configuredfor application of one or more of: transcranial electrical stimulation(TES) in the form of transcranial direct current stimulation (tDCS),transcranial alternating current stimulation (tACS), transcranialmagnetic stimulation (TMS), transcranial random noise stimulation (tRNS,e.g., band-limited random noise stimulation), transcranial variablefrequency stimulation (tVFS), band-limited stimulation transformed toincrease RMS power while minimizing transients and clipping, and anyother suitable form of TES. Furthermore, in any of the above examplesand variations, the system 100 can be configured to for delivery ofstimulation as anodal stimulation and/or cathodal stimulation. In otherexamples, the electrical stimulation can additionally or alternativelycomprise any other form of electrical stimulation (e.g., electricalmuscle stimulation, etc.) configured to stimulate any other suitableregion of the user's body, with any suitable penetration depth, and/orany suitable tissue structure (e.g., neural, musculoskeletal). In otherexamples, electrical stimulation to a body region such as the head maybe delivered using a return path including a different body region suchas the shoulder, and in such examples the electrode assembly 100 mayinclude a connector such as a socket to which an electrode cable may beconnected, or may itself include an electrode cable that may be extendedto the different body region such as the shoulder.

In some variations, robust connection with the user provided by theelements (e.g., mechanical aspects) of the system 100 additionally oralternatively applies to transmission of non-electrical modes ofstimulation according to other suitable methods. As such, the system 100can additionally or alternatively be configured to transmitnon-electrical modes of stimulation (e.g., ultrasound stimulation,optical stimulation) by using any appropriate transducer or set oftransducers in place of or in addition to electrode contacts. Forinstance, one variation of the system 100 can be used to provideultrasound transducing elements at a desired body region of the user, asfacilitated by an array of protrusions configured to displace obstaclesto ultrasound stimulation at the body region of the user. In thisvariation, ultrasound transducing elements can be configured at anysuitable position along a length of a protrusion and/or at a distal endof a protrusion. Other variations can, however, be configured toincorporate any other element(s) for stimulating the user.

However, the system 100 can implement or facilitate implementation ofany other suitable method(s).

3.1 System—Electrode Assembly.

The electrode assembly 110, as shown in FIGS. 7A-7F, functions toprovide electrical stimulation to a region of the user, such as theforehead region. Additionally or alternatively, the electrode assembly110 can function to detect and/or measure and/or record one or morebiosignals (e.g., EEG signals) from a user, provide comfort to a user,interface with a wide variety of user head morphologies, or perform anyother suitable function.

The electrode assembly 110 is preferably held against the head (e.g.,forehead, scalp, etc.) of a user through any or all of: compression, anadhesive, and/or a head assembly mechanism (e.g., strap, fastener,etc.), but can additionally or alternatively make contact with the headof a user through any other suitable mechanism. The electrode assemblycan be contoured to the head of a user through any number of curved orshaped components, compliant components, flexible components (e.g.,overall flexibility, flexibility about an inferior-superior axis,flexibility about a medial-lateral axis, etc.). In some variations, theelectrode assembly 110 can include hollow portions (e.g., channels) forthe retention and/or circulation of conductive solution (e.g., salinegel), to reduce the overall weight of the system 100, to contribute tothe flexibility and/or compliance of the system 100, etc.

The electrode assembly 110 is preferably at least partially constructedfrom one or more compliant materials (e.g., foam, sponge, polymer, gelmatrix, felt, etc.), which can function to hold and/or position one ormore electrodes against a user. Additionally or alternatively, theelectrode assembly can be constructed from one or more rigid materials(e.g., polymer, metal, etc.), which can function to add structuralstability to the system 100. Further additionally or alternatively, theelectrode assembly 110 can be at least partially constructed from any orall of: conductive materials, insulative materials, hydrophilicmaterials, hydrophobic materials, and/or any other materials.

The system 100 preferably includes a single electrode assembly 110having multiple electrodes 112, but can additionally or alternativelyinclude a single electrode assembly 110 having a single electrode 112,multiple electrode assemblies 110 (e.g., arranged on different regionsof a user's head) each having one or more electrodes 112, or any numberand combination of electrode assemblies 110. Multiple electrodes in thesame electrode assembly 110 are preferably configurable electrically bythe coupler assembly 128, but can alternatively be electricallyconnected in parallel, electrically connected in series, be connected tothe same or different coupler assemblies 128, be connected to the sameor different electronics subsystem(s) 130, or be otherwise electricallyconnected.

The system 100 can operate in one or more operation modes. In somevariations, the system 100 can include an ‘on’ operation mode and an‘off’ operation mode, wherein in the ‘on’ operation mode, one or moreelectrodes are actively applying an electrical stimulation (e.g., directcurrent) to a user and wherein in the ‘off’ operation mode, the one ormore electrodes are not actively applying an electrical stimulation(e.g., alternating current) to the user. Additionally or alternatively,the system 100 can operate in any number of additional operation modescorresponding to any number of stimulation patterns (e.g., currentdefinitions) applied by any number of electrodes. Further additionallyor alternatively, the system 100 can operate in a receiving operationmode, wherein in the receiving operation mode, one or more electrodesare measuring and/or monitoring a parameter of an associated brainregion, such as an EEG signal. The activation of and/or transitionbetween operation modes can be triggered by any suitable stimulus (timeof day, recurring, based on sensor data indicating placement of device,based on sensor data indicating readiness for or participation intraining or learning, based on sensor data indicating physiologicalresponse to stimulation, based on vital signs or biosignals such asgalvanic skin response or heart rate or heart rate variability (e.g.,user is stressed), and/or selection by user (e.g., through user device,etc.)).

3.2 System—Electrode.

The electrode assembly 100 includes a set of one or more electrodes 112(e.g., as shown in FIGS. 7A-7F, 8, 9A-9C), which can each functionand/or collectively function to apply electrical stimulation to one ormore regions of the brain. Additionally or alternatively, an electrode112 can function to detect and/or measure and/or monitor a parameter(e.g., biosignal) of brain activity.

Each of the electrodes 112 is arranged near or on the skin of a user,such as placed against a user's forehead, placed on a user's scalp(e.g., between head hairs, over head hair, etc.), placed partially overhair on a user's scalp, placed on a user's neck, placed near a user'sspinal cord, or otherwise arranged near or on a user. However, one ormore of the electrodes 112 can be arranged distal to the user's skin.The electrodes 112 can cooperatively or individually target (e.g.,electrically stimulate) one or more particular brain regions, some orall of which can be described in an electrode naming convention and/orany other neural, anatomical, radiological naming convention, such asthe 10-20 electrode system, 10-10 electrode system, 10-5 electrodesystem, the Brodmann naming convention (e.g., Brodmann areas), one ormore bone-based (e.g., skull) naming conventions, and/or any othernaming convention.

The system 100 preferably includes multiple electrodes (e.g., twoelectrodes, three electrodes, an array of electrodes, etc.), but canalternatively include a single electrode (e.g., single electrodetargeted to a specified brain region, large electrode covering multiplebrain regions, etc.). In one variation, a first electrode functions totarget (e.g., is arranged proximal to) one or more frontal lefthemispheric brain regions (e.g., F3 electrode region, left supraorbital(LSO) brain region, any electrode region, etc.) and a second electrodefunctions to target one or more frontal right hemispheric brain regions(e.g., F4 electrode region, right supraorbital (RSO) brain region, anyother electrode region, etc.). Alternatively, the two electrodes canexclusively target left hemispheric brain regions (e.g., the F3 andLSO), right hemispheric brain regions (e.g., F4 and RSO regions), or anynumber and combination of regions on any region/lobe of the brain (e.g.,cerebellum, frontal lobe, parietal lobe, temporal lobe, occipital lobe,etc.) or any other region (e.g., spinal cord) of the neural system orbody. In some variations, the electrode assembly can include three ormore electrodes (e.g., arranged proximal to the F3, F4, and RSOregions).

The set of one or more electrodes 112 is preferably arranged proximal to(e.g., overlaying, partially overlaying, next to/adjacent to, along anormal axis of, slightly displaced from, etc.) the targeted region ofinterest, but can additionally or alternatively be arranged with anoffset from a region of interest, between multiple regions of interest,overlaying multiple regions of interest, or otherwise arranged.

For example, electrodes targeting one or more regions of thedorsolateral prefrontal cortex (DLPFC) (e.g., F3 and/or F4 regions) arepreferably arranged superior to those targeting one or more supraorbital(e.g., LSO/RSO) regions, but can be otherwise arranged. The electrodeassembly preferably includes equal numbers of electrodes on either sideof the system (e.g., equal electrodes on the right and left sides of thesystem), but can alternatively include an uneven number of electrodes oneither side of the system. The electrode assembly preferably includes aDLPFC electrode and a supraorbital electrode, but can alternativelyinclude electrodes targeting any suitable region of the head.

In a first variation, the electrode assembly includes a first electrode(e.g., F3 electrode) arranged in a superior, left position (e.g., from auser's perspective), and a second electrode (e.g., RSO electrode)arranged in an inferior, right position.

In a second variation, the electrode assembly includes a first electrode(e.g., F3 electrode) arranged in a superior, left position (e.g., from auser's perspective), and a second electrode (e.g., LSO electrode) isarranged in an inferior, left position.

In a third variation, the electrode assembly includes a first electrode(e.g., F3 electrode) arranged in a superior, left position; a secondelectrode arranged in a superior, right position (e.g., F4 electrode);and a third electrode arranged in an inferior, right position.

In a fourth variation, the electrode assembly includes a singleelectrode, while the opposing side can include a cushion, strap, orother head retention mechanism that generates a compressive forceagainst the user's head. In variations using a single electrode on theelectrode assembly, a return path or reference electrode may be providedelsewhere on the body, e.g. placed on the head retention mechanism or byusing a cable extending from the electrode assembly to the return pathor reference electrode. However, the electrode assembly can include anysuitable number of electrodes in any suitable arrangement.

Different electrodes can have different geometries and/or construction(e.g., number of layers, constituent materials, etc.), but canalternatively be substantially identical. The electrode construction canbe determined based on: the targeted brain region, the location of theopposing electrode, or otherwise determined.

For example, in variants including opposing DLPFC and supraorbitalelectrodes, the DLPFC electrode (e.g., F3/F4 electrode) can have alarger stack up (e.g., a thicker hydrophilic layer 114, a thicker layerof intervening compliant foam (e.g., backing foam 118) between theconductive layer 116 and a support structure, more layers, lofted abovea user forehead by a headpiece, etc.) than a supraorbital electrode(e.g., LSO/RSO electrode, which can lack compliant foam or include athinner layer of compliant foam). This configuration can enable thesystem to conform to different head sizes and/or prevent system pivoting(e.g. pivoting of the system 100 around the axis defined by the linebetween the contact patches of two electrodes) due to the offset usercontact points. The plane of the DLPFC electrode or portion thereof(e.g., conductive layer 116, hydrophilic layer 114, support structure118, etc.) can be offset (e.g., elevated, lofted, etc.) from the planeof the supraorbital electrode or portion thereof by 0.1 mm, 1 mm, 5 mm,10 mm, 20 mm, between 0.1 mm-10 mm, or by any suitable distance.However, the DLPFC electrode can be thinner than the supraorbitalelectrode (e.g., be closer to the user than the supraorbital electrode),be the same thickness (and/or have the same geometry, construction,and/or arrangement as) the supraorbital electrode, or be otherwiseconfigured or arranged relative to the supraorbital electrode.

In some variations, two or more electrodes are arranged with apredetermined orientation and spacing with respect to each other, whichcan function to properly conform to a surface of the user (e.g., theforehead of a user) and/or a wide variety of users. In one variation,the angle between a tangent plane of a first electrode and a tangentplane of a second electrode can have a value of 13.5 degrees, a valuebetween 5 and 20 degrees, a value between 8.5 and 18.5 degrees, a valuebetween 10 and 15 degrees, or any other value or range of values. In aspecific example, for instance, the angle between a first tangent planeand a second tangent plane, the first tangent plane tangent to a firstcenter point of an inner broad surface of a first of the set ofelectrodes and the second tangent plane tangent to a second center pointof an inner broad surface of a second of the set of electrodes, has avalue between 8.5 and 18.5 degrees. In the variation shown in FIGS.9A-9C, any or all of a set of spacings/dimensions (e.g., D1-D6) and/orany or all of a set of orientations/angles (e.g., A1-A8) can be used tolocate one or more electrodes with respect to the other electrode(s). Ina first example (e.g., in a relatively rigid electrode assembly 110),the dimensions D1-D6 have values of approximately or exactly 79millimeters (mm), 41 mm, 40 mm, 30 mm, 17.5 mm, and 60 mm, respectively,and the angles A1-A8 have values of approximately or exactly 2.75degrees (deg), 13.5 deg, 26.5 deg, 50 deg, 75 deg, 11.5 deg, 25.5 deg,and 20 deg, respectively. In a second example (e.g., in a moderatelyflexible electrode assembly 110), the dimensions D1-D6 can take onvalues of 79±15 mm, 41±15 mm, 40±10 mm, 30±10 mm, 17.5±10 mm, 60±10 mm,respectively, and the angles A1-A8 have values of approximately orexactly 2.75±5 deg, 13.5±5 deg, 26.5±10 deg, 50±10 deg, 75±20 deg,11.5±15 deg, 25.5±15 deg, and 20±15 deg, respectively. In a thirdexample (e.g., in a flexible electrode assembly 110), the dimensionsD1-D6 can take on values of 79±25 mm, 41±25 mm, 40±20 mm, 30±20 mm,17.5±20 mm, and 60±20 mm, respectively, and the angles A1-A8 can take onvalues of 2.75±15 deg, 13.5±15 deg, 26.5±20 deg, 50±20 deg, 75±40 deg,11.5±25 deg, 25.5±25 deg, and 20±25 deg, respectively. In a fourthexample, the dimensions D1-D6 have values of approximately or exactly 84mm, 40 mm, 40 mm, 35 mm, 14.5 mm, and 60 mm, respectively, and theangles A1-A8 have values of approximately or exactly 2.75 degrees, 13.5degrees, 31 degrees, 50 degrees, 70 degrees, 11.5 degrees, 25.5 degrees,and 20 degrees, respectively. In a fifth example, the dimensions D1-D6can take on values of 84±15 mm, 40±15 mm, 40±10 mm, 35±10 mm, 14.5±10mm, and 60±10 mm, respectively, and the angles A1-A8 can take on valuesof 2.75±5 degrees, 13.5±5 degrees, 31±10 degrees, 50±10 degrees, 70±20degrees, 11.5±15 degrees, 25.5±15 degrees, and 20±15 degrees,respectively. Additionally or alternatively, any of these dimensionsand/or angles or any other set of dimensions and angles can take on anysuitable range of values in order to conform to a head of a user.

In one variation, as seen in FIG. 3, the electrode assembly 110 caninclude one or more electrodes arranged over any or all of: an F3electrode region, an F4 electrode region, an LSO region, and an RSOregion. In one example of this variation, the electrode assembly 100 canfurther include any number of electrodes arranged between any or all ofthe electrode regions (e.g., between the F4 and F3 electrodes), adjacentany or all of the electrode regions (e.g., adjacent an RSO electrode),and/or any number of electrodes arranged anywhere on the head of a user.

In a second variation, one or more electrodes can be arranged with anonzero spacing with respect to one or more edges of a head assemblymechanism 170. In one example, for instance, an electrode can beelectrically connected to a coupler assembly 128 (e.g., with a cable)and adhered to a user (e.g., with an adhesive) with a physicalseparation from the head assembly mechanism 170 (e.g., headband).

Each of the electrodes 112 is preferably constructed to have a curvature(e.g., a curvature of a broad surface, a set of curvatures of a broadsurface, one or more curvatures of any other surface, etc.), which canfunction to conform to a region (e.g., forehead) of the user to providecomfort, facilitate proper placement, maintain proper placement, etc.Additionally or alternatively, one or more electrodes 112 can beconstructed with a flat surface. In some variations, the electrodes 112are constructed from a material compliant and/or thin enough to conformto a user without requiring one or more curved surfaces, or may beconstructed to have a convex curvature and from a material that iscompliant and/or thin enough that part or all of the convex curvatureassumes a substantially concave shape and conforms to a region of theuser when pressed against this region of the user.

Each of the electrodes 112 is preferably substantially rectangular(e.g., rectangular with rounded corners) in shape (e.g.,outline/projection of a broad surface), but can additionally oralternatively be circular, ovoid, or have any other suitable shape. In aset of two or more electrodes 112, the electrodes 112 can have the sameshape and size, different shapes (e.g., to cover/contour brain regionsin different locations), and/or different sizes (e.g., to coverdifferent sizes brain regions, different numbers of brain regions,etc.).

The surface of the electrode 112 arranged closest (e.g., most proximal)to the user (e.g., an inner broad surface; active surface; userinterface) can be smooth (e.g., for enhanced comfort of the user),textured (e.g., to enhance retention of a conductive solution), includeone or more protrusions (e.g., array or series of ridges, sphericalbodies, pyramidal bodies, tubular bodies, etc. to comb through hair orotherwise improve electrode-user contact) as shown in FIG. 8, or haveany other surface. The protrusions (e.g., bumps, merlons, ridges, nibs,comb teeth, pyramidal extensions, etc.) can be immediately adjacent(e.g., contiguous), be separated by spaces (e.g., crenels), or beotherwise configured. The protrusions are preferably compliant, but canalternatively be rigid or have any suitable stiffness. The surfaces ofthe protrusions proximal to the user (e.g., inner surfaces) can be flat,curved (e.g., convex, with a 1 mm radius or any suitable radius;concave, etc.), pointed, or otherwise configured. The protrusions arepreferably arranged in a regular pattern or array on the electrode(e.g., wherein linear protrusions are arranged in parallel), but canalternatively be arranged in a matrix or in any suitable pattern. In oneexample, the protrusions are arranged with the ridges parallel to thevertical axis of the headpiece (e.g., an inferior-superior axis of thehousing), with a projection parallel to the user's sagittal plane, orotherwise arranged. Additionally, any distal and edge surfaces of eachelectrode 112 can be smooth, textured, include one or more protrusions,or have any other surface.

Different electrodes 112 can have different inner broad surfaces, orhave the same inner broad surfaces. In one example, the DLPFC electrodescan have protrusions, while the supraorbital electrodes can be flat.However, the DLPFC electrodes can be flat or otherwise configured, andthe supraorbital electrodes can include protrusions or be otherwiseconfigured.

Each of the electrodes and/or components thereof can be constructed fromany or all of: a lamination procedure/process (e.g., foam and fabriclamination), a thermoforming process, one or more adhesive connections,one or more mechanical connections (e.g., retaining ring, grommets,sewing, etc.), a molding process (e.g., co-molding, injection molding,compression molding), an extrusion process, or any other method orprocess of manufacture.

Each of the electrodes 112 preferably includes two or more layersincluding a hydrophilic layer 114 (e.g., hydrophilic foam) and aconductive layer 116 (e.g., conductive polymer). Alternatively oradditionally, one or more electrodes 112 can include a single layer(e.g., a conductive layer, a compliant conductive layer, a hydrophilicconductive layer, etc.), an insulative layer, a stiffening layer, and/orany other combination of layers.

3.3 System—Hydrophilic Layer.

Each electrode 112 can include a hydrophilic layer 114, which canfunction to provide comfort to a user, retain a conductive solution(e.g., liquid electrolyte, conductive gel, conductive powder, salinesolution, water, etc.), emit a conductive solution, conform to a varietyof head morphologies, maintain electrode placement, or perform any othersuitable function. The hydrophilic layer 114 is preferably the innermostlayer (e.g., layer closest to the user, active layer, user interfacelayer, etc.) of the electrode 112 and defines an active face that isplaced against the user (e.g., on the user's forehead), but canadditionally or alternatively be arranged further away from the userwith respect to another layer of the electrode 112 (e.g., behind anotherlayer of the electrode 112, distal the user, etc.), form multiple layersof the electrode 112, or be arranged in any other way. The hydrophiliclayer 114 may be constructed of a material that is fundamentallyhydrophilic, such as cellulose or polyvinyl alcohol foam, or may beconstructed of a material that is hydrophobic but is made hydrophilic bytreatment such as with a surfactant.

The hydrophilic layer 114 is preferably constructed to have a curvatureto conform to a user (e.g., be concave toward an active face, be convextoward the active face), but can alternatively be flat. The hydrophiliclayer 114 can be rectangular (e.g., with rounded corners) in shape(e.g., shape of a broad surface of the hydrophilic layer 114, an outlineor profile of the hydrophilic layer 114, etc.), circular, ovoid, or haveany other shape. One or more surfaces can be smooth, textured (e.g., toretain a conductive solution), include one or more protrusions, or haveany other surface type. In some variations (e.g., as shown in FIG. 8),the hydrophilic layer 114 is constructed with an array of surfaceprotrusions (e.g., ridges, nibs, comb teeth, pyramidal extensions),which can function to enhance the distribution or retention of aconductive solution, reach the skin of a user (e.g., comb through hair),increase compliance/comfort of the electrode 112, or perform any othersuitable function. In some variations, the hydrophilic layer 114 canhave a thickness of exactly or approximately 4 mm uncompressed. In othervariations, the hydrophilic layer 114 can have a thickness of exactly orapproximately 2 mm uncompressed. In other variations, the hydrophiliclayer 114 can have a thickness between 1 mm and 6 mm uncompressed, lessthan 10 mm uncompressed, or have any other thickness or range ofthicknesses.

The hydrophilic layer 114 is preferably constructed from a porousmaterial, but can alternatively be constructed from any suitablematerial. The porosity of the hydrophilic layer can include a range ofpore sizes, have a substantially uniform pore size throughout, include agradient of pore sizes (e.g., increasing from back to front, from rightto left, or in any suitable direction along any suitable axis), orinclude any suitable distribution of pore sizes. The pore sizes can bebetween 10 micrometers-10,000 micrometers, 100-1,000 micrometers, or beany suitable pore size. The hydrophilic layer 114 is preferablyconstructed from a hydrophilic foam, such as a polyvinyl acetate (PVA)foam or sponge. Additionally or alternatively, the hydrophilic layer 114can be constructed from a sponge, a hydrophobic foam, a cellulose foam,a shape memory foam, a comfort foam, polyolefin, cellulose, polyvinylacetate sponge, a woven or sintered porous material, or a nonwoven feltmaterial such as felted or extruded nylon fibers, cellulose fibers, amixture of nylon and cellulose fibers, a closed-cell foam, an open-cellfoam, a polymer (e.g., swellable polymer, swellable silicone, swellablegel, etc.), or any other suitable hydrophilic and/or compliant and/orporous material. In some variations, the hydrophilic layer 114 isfurther constructed from a conductive material, such as a conductivepowder integrated within or on a surface of the foam. The hydrophiliclayer 114 is preferably constructed from a relatively compliant material(e.g., elastic modulus less than 20 MPa, less than 50 MPa, less than 100MPa, less than 1 GPa, between 20 and 100 MPa, etc.), but canadditionally or alternatively be constructed from a relatively stiffmaterial, or a material having any suitable properties.

The electrode 112 can include any number of hydrophilic layers 114. Insome variations, the electrode includes a single hydrophilic layer 114against the user's skin. In other variations, the electrode 112 caninclude one or more additional hydrophilic layers 114 (e.g., of higherstiffness than the first hydrophilic layer 114), which can function tobetter conform to the user, increase a thickness of the electrode 112,shield layers from a conductive fluid, retain a greater volume ofconductive fluid, increase user comfort, or perform any other suitablefunction. Multiple hydrophilic layers 114 can be stacked along theelectrode thickness, arrayed along the electrode height or width, orotherwise arranged.

The hydrophilic layer 114 preferably includes and/or provides aninterface (e.g., conductive interface) between the electrode 112 and theuser's skin. In some embodiments, this interface is provided in the formof a liquid electrolyte (e.g. 0.9% saline solution) carried by ahydrophilic layer 114. In some embodiments, the electrolyte is producedby the combination of water applied by the user (e.g. by splashing,spraying, or other means) mixing with salt (e.g. sodium chloride)pre-embedded (e.g. by drying of a brine solution in a porous hydrophiliclayer 114), or otherwise created.

3.4 System—Conductive Substrate.

Each electrode can include one or more electrically conductivesubstrates 116 (e.g., conductive backing). The conductive substrate 116can function to establish an electrical connection between a hydrophiliclayer 114 and another component of the system (e.g., stimulus generator,neurostimulation circuitry), for instance by forming a normal electronicconnection to the neurostimulation circuitry and by forming anelectrode-to-electrolyte interface with an electrolyte fluid containedwithin the hydrophilic layer. Additionally or alternatively, theconductive substrate 116 can function to establish an electricalconnection between a hydrophilic layer 114 and another layer of theelectrode 112, apply an electrical stimulation to a user, contributestructural support to an electrode 112, or perform any other suitablefunction.

The conductive substrate 116 is preferably arranged further away fromthe user (e.g., distally) than other layers of the electrode 112 but canadditionally or alternatively be arranged closer to the user than otherlayers of the electrode, be the sole component of an electrode, bearranged along a perimeter of the electrode, or have any other suitablearrangement. The conductive substrate 116 is preferably positioned toform an electrode-to-electrolyte interface with electrolyte fluid or gelcontained within the hydrophilic layer 114 and can additionally oralternatively be mechanically connected to the hydrophilic layer 114(e.g., serve as a backing to the foam layer 114), electrically connectedto the hydrophilic layer 114, and/or arranged in any other suitable way.

The conductive substrate 116 is preferably a similar shape as thehydrophilic layer 114, such that the conductive substrate 116 can bestacked/layered with the hydrophilic layer 114 and/or any other layersof the electrode 112, which can collectively function to conform to ahead region (e.g., forehead) of the user. The conductive substrate 116may include a proximal (e.g., toward the user) surface with geometricfeatures such as ridges, bumps, or nibs that mate with inverse featurespresent on the distal (e.g., away from the user) surface of thehydrophilic layer 114, to increase surface area of the interface betweenthe conductive substrate 116 and hydrophilic layer 114 and/or minimizethe path length between any point on the proximal (i.e., toward theuser) surface of the hydrophilic layer 114 and the closest point on theconductive substrate 116. Additionally or alternatively, the conductivesubstrate 116 can be smaller than the hydrophilic layer 114 or have anyother shape or size. The conductive substrate 116 is preferably between0.1-1 mm thick, such as 0.8 mm thick, but can have any suitablethickness. In some variations, the conductive substrate 116 includes aframe (e.g., a support frame), wherein the frame can be arranged betweenthe user and the conductive backing (e.g., as shown in FIG. 7C), whichcan function to electrically connect any or all of the conductivebacking 116 to any or all of the electrode 112. Additionally oralternatively, the frame can be arranged to the side (e.g., medially,laterally, etc.) of the conductive backing, behind the conductivebacking, along a perimeter of the electrode 112 or along/within anyother region of the electrode 112. The conductive substrate 116 canadditionally or alternatively include a frame extending in any otherdirection, a ring encircling the conductive substrate 116 and/or anyother layer(s) of the electrode 112, or any other feature or component.In some variations, the conductive substrate 116 is simply a conductivecomponent (e.g., metallic wire, clamp, bracket, etc.) attached to thehydrophilic layer (e.g., flexible foam) 114.

The conductive substrate 116 is constructed from an electricallyconductive material. Preferably, the electrically conductive material isa conductive polymer, such as a conductive rubber (e.g., carbon rubber,conductive silicone rubber, nickel-graphite carbon rubber, graphiteconductive rubber, silver copper silicone conductive rubber, etc.) orany other suitable conductive material. Additionally or alternatively,the conductive substrate 116 can include purely metallic materials(e.g., copper wire, gold plate, etc.), or any other conductivematerial(s) arranged in any suitable way.

In some variations, the conductive substrate 116 includes an electricalcoupler, which functions to electrically and/or mechanically connect theconductive substrate 116 to another electrical component of the system100, such as to a coupler assembly 128 (e.g., one or more elements of anelectronics subsystem 130 within the coupler assembly 128) via anelectrical attachment system 150 (e.g., conductive polymer body). Theelectrical coupler is preferably arranged along a second broad face ofthe electrode opposing the active surface of the electrode (e.g.,arranged along the back of the electrode), but can alternatively bearranged along a side of the electrode, arranged along the activesurface of the electrode (e.g., along the front of the electrode), or beotherwise arranged. The electrical coupler can be arranged along aportion of an electrode broad face, a protrusion extending from theelectrode side, or have any suitable geometry. The electrical coupler ispreferably flexible (e.g., with an elastic modulus less than 0.1 GPa),but can alternatively be stiff (e.g., with an elastic modulus of 50-90GPa), or have any suitable stiffness.

In one example, the electrical coupler is a portion of the conductivesubstrate 116, such a conductive polymer extension (e.g., an extruded ormolded conductive polymer arm; an extension of the conductive polymerfrom a side edge of the electrode 112, along the conductive substrateplane; etc.) or simply a surface of the conductive substrate 116 (e.g.,a portion of the conductive surface broad face, such as a portiontracing the conductive substrate perimeter, an inner portion, a medialportion; etc), which makes contact with another electrical component ofthe system 100. In another example, the electrical coupler is a frame(e.g., conductive polymer frame connecting two or more electrodestogether, a metallic frame, etc.). In a third example, the electricalcoupler is one or more conductive wires (e.g., copper wires) attached toone or more conductive substrates 116.

Preferably there is one conductive substrate 116 for each electrode 112in the device, but there can additionally or alternatively be multipleconductive substrates 116 for a single electrode (e.g., distributedthroughout a multi-layer electrode), a single conductive substrate 116for multiple electrodes 112, or any number and arrangement of conductivesubstrates 116.

3.5 System—Support Structure.

The electrode 112 can include one or more support structures 118 (e.g.,support layers), which can function to add structural stability to theelectrode 112, retain one or more components (e.g., layers) of theelectrode 112, attach and/or detach an electrode 112 from the system100, establish an electrical and/or mechanical connection betweencomponents of the electrode 112, conform to the head of a user (e.g., byincreasing the thickness of the electrode 112) and/or attach to the headof a user, or perform any other suitable function.

The support structure 118 can be of a similar shape and/or size as oneor more layers of the electrode 112 (e.g., the hydrophilic layer 114),and span all or a majority of the electrode. This can allow, forinstance, the support layer 118 to be easily stacked/layered with (e.g.,in a recess of an adjacent layer of the electrode 112), laminatedbetween, adhered to, embedded, molded, or otherwise arranged with one ormore other layers/components of the electrode 112. In one example, thesupport structure 118 can be arranged (e.g., laminated) between a layerof insulating material and a layer of conductive substrate 116. In asecond example, the support structure can be embedded within theconductive substrate 116 or other layer. However, the support structure118 can span a portion of the electrode, such as the electrical couplerarea of the electrode, extend along the edges of the electrode, extenduniaxially (e.g., along the electrode longitudinal axis, lateral axis,etc.), or along any suitable portion of the electrode.

The support structure preferably includes a material layer (e.g., acontinuous layer, a woven layer, etc.), but can additionally oralternatively, the support structure 118 can include a frame (e.g.,conductive frame electrically connected to the conductive substrate,polymer frame arranged around the perimeter of the electrode 112,polymer frame arranged between layers of the electrode 112, etc.), aring (e.g., retaining ring holding multiple layers of the electrode 112together, snap ring, etc.), reinforcement plate (e.g., metallic plate,polymer plate, magnetic plate, etc.), set of posts (e.g., arrangedwithin or between layers of the electrode 112; arranged in an array;arranged in a radiating pattern from a central or peripheral connectionpoint to one or more edges of the electrode; linked or intersecting;cooperatively forming a truss; etc.), mesh layer or lining, or any otherform factor in any arrangement.

The support structure(s) 118 is preferably pre-curved (e.g., with theradius of the electrode; with a radius smaller or larger than a scalpcurvature at the target location), but can alternatively or additionallybe flat, sinusoidal, or have any suitable geometry. In one variant, thesupport structure 118 is pre-curved with a radius smaller than the scalpcurvature. In this variant, the support structure stiffness ispreferably relatively low (e.g., between 20 GPa-60 Gpa), which canresult in a large geometric change but a low applied force whenconforming to the scalp. This can allow the elastic forces on the scalpto be approximately identical for a wide variety of curvatures.

The support structure 118 can be constructed from any suitable material,and in variations of the electrode 112 having multiple supportstructures 118, the support structures 118 can be constructed from thesame or different materials. In some variations, the support structure118 is relatively compliant, such as a foam or sponge, fabric (e.g.,felt), inflatable element, polymer (e.g., rubber, silicone, resin,polyoxymethylene etc.), metallic springs (e.g., stamped, formed,printed, etc.), or other material. In a specific example, for instance,the support structure 118 can be a backing foam arranged behind (e.g.,adjacent a broad surface away from the head of a user) a hydrophiliclayer 114. The backing foam can be arranged in a recess of thehydrophilic layer 114, adhered to a surface (e.g., outer broad surface,inner surface, edge surface, etc.) of the hydrophilic layer 114, be heldby compression of the device, or otherwise arranged. In othervariations, the hydrophilic layer 114 is made of a relatively rigidmaterial, such as a polymer (e.g., stiff plastic), metal, conductivepolymer (e.g., conductive substrate), etc. In one example, for instance,the support structure 118 can include an electrode frame, wherein theelectrode frame is arranged between a hydrophilic layer 114 and aconductive substrate 116. In a specific example, the electrode frame canfunction to establish an electrical connection between the hydrophiliclayer 114 and the conductive substrate 116 but can additionally oralternatively function to establish a mechanical connection, providemechanical support, or perform any other function. In another specificexample, the support structure 118 can be an attachment piece, such as aring (e.g., snap ring, retaining ring, clamp, etc.) configured to holdelements of the electrode 112 together or to connect the electrode 112to other components of the system 100.

The electrode 112 can further include any number of insulative materials(e.g., as shown in FIG. 8), which can function to protect a user and/orany element of the system 100, facilitate a proper electrical connectionbetween components elsewhere in the system 100, and/or perform any othersuitable function. In one variant, the insulative material canelectrically isolate the electronic conducting material from all or partof the environment, which can isolate electrochemical reactions to theactive face of the conductive substrate 116 (e.g., the face contactingelectrolyte in the hydrophilic layer 114). The insulative material canbe arranged behind the conductive substrate 116, between the hydrophilicmaterial and the support structure, or otherwise arranged. Theinsulative material preferably extends along the entire broad face ofthe electrode 112 in a layer, but can extend along only a portion of theelectrode 112. In one example, the insulative material can be between0.01-0.5 mm thick, such as 0.1 mm thick, but can have any suitablethickness. Alternatively, the electrode can lack insulative materials orlayers. The insulative material is preferably electrically insulative,but can alternatively or additionally be fluidly insulative (e.g.,fluid-impermeable, hydrophilic, etc.) or have any suitable fluidproperty.

3.6 System—Fasteners.

The electrode 112, and/or any other component(s) of the system 100, caninclude any number, type, and arrangement of fasteners (e.g., fastenerassemblies), wherein the fasteners function to hold one or more elementsof the system 100 together. These can include any or all of: anadhesive, screw, nail, tie (e.g., nylon tie), gasket, press-fitconnector (e.g., press-fit bollards), sewn element, ring (e.g., O-ring),seal (e.g., face seal, boss seal, dovetail seal, reciprocating seal,laminated seal, etc.), magnet, joint, hook-and-loop fastener, button,snap, strap, buckle (e.g., watch strap buckle), clamp, and/or any othersuitable fastening component and/or means for fastening/attaching.

In one variation, the layers of the electrode 112 are laminatedtogether.

In a second variation, the electrode 112 is attached to the system 100using a face seal.

In a third variation, a set of magnets is used to retain the position(s)of one or more electrodes relative to an adjacent element of the system100, such as a foam support.

3.7 System—Electrode Housing.

The system 100 preferably includes an electrode housing 120 (e.g., asshown in FIGS. 7A-7E), which can function to support one or moreelectrodes 112, separate one or more electrodes 112 from each other,conform to the head of a user, serve as an attachment point for anothercomponent of the system, or perform any other function.

The electrode housing 120 (e.g., compliant base) can be connected to oneor more electrodes 112, preferably at an inner broad surface (e.g.,surface closest to the user, active surface, user interface, etc.) ofthe electrode housing, such that a broad surface (e.g., inner broadsurface, active surface, user interface surface, etc.) of the electrode112 is exposed and configured to be placed against the user.

The electrode housing 120 can include one or more retention mechanismsthat function to mechanically retain the electrodes 112. The retentionmechanism can optionally form a mechanically stable joint and fluidlyseal the electrical connection from fluid ingress. The retentionmechanisms preferably include recesses for the electrodes 112, whereinthe electrodes 112 can be placed within the recesses. The recesses arepreferably complimentary to the electrode profile, but can alternativelyhave any suitable shape. The electrodes 112 are preferably press-fitinto the recesses, but can alternatively be retained by an interferencefit, be retained by an electrode tongue fitting within a recess groove,or be otherwise mechanically retained. The recesses can optionallyinclude compliance mechanisms arranged therein that facilitate electrode112 deformation relative to the electrode housing 120. Examples ofcompliance mechanisms that can be used include: springs (e.g., biasingthe electrodes away from the electrode housing 120, dampers, foam, orother deformation mechanisms capable of applying a restorative forceagainst the retained electrode 112. Additionally or alternatively, theelectrodes 112 can be attached using an adhesive, sewn into theelectrode housing, co-molded with the electrode housing, attachedthrough a lamination process, attached using a mechanical connection(e.g., press fit, gasket, interlocking strips, bollards, screws, etc.),attached by complimentary magnet arrays cooperatively generating anattractive force, or otherwise connected.

In some variations, an electrical coupler (e.g., conductive polymerframe) connected to one or more conductive substrates 116 can extendthrough the electrode housing 120. This can function, for instance, toestablish an electrical connection between one or more conductivesubstrate(s) 116 and an electronic component of the system (e.g.,controller, stimulus generator, etc.). In a specific example, forinstance, two conductive substrates 116 can have electrical couplerextensions which converge in a common electrical coupler frame, whereinthe electrical coupler frame extends through the electrode housing in adirection away from the user (e.g., along a normal axis of the user'sforehead).

The electrical coupler(s) of one or more electrodes 112 preferablyaligns with an electronic coupling assembly (e.g., conductive polymerbody, attachment system 150 piece, etc.) of the electrode housing 120when the electrode 112 is mounted to the electrode housing 120, but canalternatively be offset. In one variation, the electrode housing 120includes a gasket, bead, raised strip, or other sealing mechanismencircling all or a portion of the electronic coupling assembly. Inanother variation, the electrode 112 includes a gasket, bead, raisedstrip, or other sealing mechanism encircling all or a portion of theelectrical coupler. In yet another variation, both the electrode housing120 and the electrode 112 include a gasket, bead, raised strip or othersealing mechanism. The sealing mechanism can be formed from theinsulating layer, the support layer, secondary material, such as plasticor elastomer, or any suitable material. The opposing surface canoptionally include a complimentary groove that seats the sealingmechanism. The sealing mechanism can function to form afluid-impermeable seal (e.g., watertight seal, fluid-impermeable seal,etc.) against the opposing surface of the complimentary component (e.g.,electrode housing 120 or electrode 112).

The electronic coupling assembly (e.g., attachment system 150) of theelectrode housing can be integrated with the retention mechanism of theelectrode housing, be adjacent to, paired with, proximal, concentricwith, distant from, or be otherwise arranged relative to the retentionmechanism.

The electrode housing 120 preferably includes one or more curved broadsurfaces and/or curved edges, the curved surfaces/edges configured toconform to one or more parts of the user head, such as the forehead,scalp, ear, back of the head/neck, or any other part of the user.Alternatively, the electrode housing 120 can include only straightsurfaces/edges (e.g., when the electrode housing 120 is constructed froma compliant material).

The electrode housing 120 is preferably constructed from a relativelyflexible and/or compliant material (e.g., elastic modulus less than 3GPa, less than 2 GPa, less than 1 GPa, less than 100 MPa, between 20 and50 MPa, etc.), which can help the system 100 better conform to a varietyof head shapes and sizes. The electrode housing 120 can be constructedfrom a foam or sponge, polymer (e.g., rubber, silicone, etc.), fabric(e.g., Nylon fabric, reinforced fabric, non-woven fabric, etc.), or anyother material. Additionally or alternatively, the electrode housing 120can be constructed (e.g., using 3D-printing or molding/casting based onuser dimensions) from a rigid material (e.g., to add structural support,maintain electrode positions), such as a polymer (e.g., rubber, plastic,etc.), metal, or any other suitable material. Additionally oralternatively, the electrode housing 120 can have a nonuniform rigidity.For example, the portions of the electrode housing 120 behind theelectrodes 112 can be flexible, while the remainder of the electrodehousing 120 can be rigid. In a second example, the portions of theelectrode housing 120 behind the electrodes 112 can be rigid, while theremainder of the electrode housing 120 can be flexible. However, theelectrode housing 120 can be otherwise constructed.

The electrode housing 120 is preferably constructed from a hydrophobicmaterial, which can function to repel a conductive solution (e.g.,saline electrode gel), repel perspiration from a user, or perform anyother function. Additionally or alternatively, the electrode housing canbe only partially hydrophobic, or not hydrophobic at all. In somevariations, the electrode housing 120 can function to hold the device inplace on a user. An electrode housing 120 can, for example, consist of aframe which at least partially circumferentially wraps around the headof a user and holds a set of electrodes in place. In some variations,the electrode housing 120 is constructed from a combination of compliantand rigid materials (e.g. a plastic frame encased in foam).

The electrode housing 120 can include a single piece, a single piece foreach electrode, multiple pieces for a single electrode, multiple layeredpieces, or any number and arrangement of pieces. In some variations, theelectrode housing 120 includes an inner piece connected to an outerpiece, the electrodes mounted to the inner piece.

In a first variation, the electrode 112 includes a hydrophilic electrodefoam 114 placed against the user, followed by, in a direction away fromthe user (e.g., along a normal axis of the user's forehead), a backingfoam 118, electrode frame 118, snap ring 118, and conductive polymer(e.g., carbon rubber) backing 116, the conductive polymer backing 116including a conductive polymer frame (e.g., further attached to a secondelectrode 112) which extends through foam electrode housing 120.

In a second variation, the electrode 112 includes a foam layer 114attached to a conductive backing 116.

In a third variation, the electrode 112 includes a conductive backing116 and a conductive solution (e.g., saline solution).

In a fourth variation, the electrode 112 includes a hydrophilic layer114 layered over a conductive substrate 116 which is then layered overan insulative material.

3.8 System—Coupler Assembly.

The system 100 can include a coupler assembly 128 (e.g., as shown inFIGS. 5A-5C and 6A-6B), which functions to connect the any or all of theelectrode assembly 110 to a head apparel assembly 170. Additionally oralternatively, the coupler assembly 128 can function to connect any orall of the electrode assembly 110 to a cosmetic outer element 160, toapply an electrical stimulation to one or more electrodes 112, toprotect one or more electronic components, and/or perform any othersuitable function. In embodiments and variations, the coupler assembly128 may be integrated with one or more electrode assemblies 110 and/orone or more head apparel assemblies 170; the coupler assembly 128 mayalso connect only to one or more electrode assemblies no and not to ahead apparel assembly 170, for instance if the coupler assembly isdesigned to be held to the head by the user during use of the system100.

The coupler assembly 128 includes an electronics subsystem 130, as shownin FIGS. 5A-5C and 6A-6B, which functions to apply an electricalstimulation to one or more electrodes 112. Additionally oralternatively, the electronics subsystem 130 can function to power thesystem 100 and/or connect the system 100 to an external power source,monitor neural activity of a user, receive input(s) (e.g., desiredoperation modes) from a user, send output(s) (e.g., notifications) to auser, or perform any other function.

The electronics subsystem 130 is preferably connected to the electrodeassembly 110 and preferably arranged behind the electrode assembly 110(e.g., further away from the user). Additionally or alternatively, theelectronics subsystem 130 can be connected to any component of thesystem, make contact with the user, or be otherwise arranged. The devicepreferably includes one electronics subsystem 130, but can additionallyor alternatively include multiple electronics subsystems, an electronicsubsystem in communication with an external electronics subsystem (e.g.,a user device such as a mobile phone), or any number of electronicsubsystems 130.

The electronics subsystem 130 preferably includes an electronics base,such as a printed circuit board (PCB), a breadboard, or any othersuitable base, wherein the electronics base functions to mechanicallysupport and/or electrically connect components of the electronicssubsystem 130. Additionally or alternatively, the electronics base caninclude a set of conductive wires, wherein the wires electricallyconnect components of the electronics subsystem 130. Components of theelectronics module 130 can additionally or alternatively be mechanicallysupported by other elements of the system, such as an electronicshousing or an electrode housing 120, or not mechanically supported inany specific arrangement. In one variation, the electronics subsystem130 is mounted behind one or more of the electrodes 112 (e.g., distalfrom the user) within the electrode housing 120.

3.9 System—Control Module.

The electronics subsystem 130 preferably includes a control module(e.g., controller, processor, etc.) 134, which functions to apply anelectrical stimulus (e.g., through a stimulus generator) to a userthrough one or more electrodes 112. Additionally or alternatively, thecontrol module 134 can function to store electrical stimulus patterns,share electrical stimulus patterns (e.g., between users through anapplication on a user device, the cloud, etc.), monitor deviceperformance, implement a fail-safe (e.g., power shut-off in the event ofoverheating or stimulus parameter above a predetermined threshold,alarm, etc.), monitor and/or measure neural activity of a user, storeand/or share neural activity recordings, or perform any other suitablefunction.

The control module 134 is preferably electrically connected to theelectrode assembly 110, more preferably to one or more conductivebackings 116, but can additionally or alternatively be in wirelesscommunication with the electrode assembly 110 and/or any other elementin the system 100. In one example, for instance, a stimulusgenerator/deliverer onboard the system 100 can be controlled (e.g.,wirelessly) from a remote source, such as a processor in a user deviceor a remote server system. An onboard control module 134 is preferablyconnected (mechanically and/or electrically) to an electronics base(e.g., PCB) but can otherwise be arranged anywhere else in the system.In variations having an onboard control module 134, the onboard controlmodule 134 can be wirelessly coupled to a control module 134 of anexternal device, such as a user device. Examples of the user deviceinclude a tablet, smartphone, mobile phone, laptop, watch, wearabledevice (e.g., glasses), or any other suitable user device. The userdevice can include power storage (e.g., a battery), processing systems(e.g., CPU, GPU, memory, etc.), user outputs (e.g., display, speaker,vibration mechanism, etc.), user inputs (e.g., a keyboard, touchscreen,microphone, etc.), a location system (e.g., a GPS system), sensors(e.g., optical sensors, such as light sensors and cameras, orientationsensors, such as accelerometers, gyroscopes, and altimeters, audiosensors, such as microphones, etc.), data communication system (e.g., aWiFi transceiver(s), Bluetooth transceiver(s), cellular transceiver(s),etc.), or any other suitable component.

The control module 134 preferably includes one or more of: a controller(e.g., a microcontroller), processor (e.g., a microprocessor), system ona chip (SoC) or other integrated circuit, timing subsystem including aset of timers, and/or stimulus generator (e.g., multi-channel stimulusgenerator, set of stimulation control instructions, etc.), but canadditionally or alternatively include any other circuitry, electroniccomponent, or control unit configured to apply an electrical stimulus toa user.

The control module 134 can include data storage (e.g., to storestimulation patterns), which can be onboard the system 100 (e.g., in theform of a memory chip, memory card, etc.) or external to the system 100(e.g., via wireless communication with a remote server, the cloud,etc.).

The control module 134 can also include a sensor system mounted to orintegrated within any part of the system 100 (e.g., attached to theelectrode housing 120, attached to the electronics housing 144, etc.).The system 100 can, for instance, include any one or more of: a moisturesensor, pressure sensor, contact sensor, optical sensor (e.g., lightsensor, camera, etc.), orientation sensor (e.g., accelerometer,gyroscope, altimeter, etc.), audio sensor (e.g., microphone), or anyother sensor. The sensor system can be used to implement fail-safes(e.g., activate alarm based on temperature sensor data and/or stimulusgenerator data), determine/trigger operational modes, or can be used forany other purpose.

In some variations, the control module 134 further includes one or morewireless communication components, such as an antenna, WiFi chip,Bluetooth chip, a near-field communication (NFC) system (e.g., NFC tag,NFC chip, etc., e.g. used for identification of an NFC-readable tag inthe electrode assembly 110 for purposes such as confirming usage of thecorrect type of electrode assembly 110 or suggesting or requiringreplacement of the electrode assembly 110 after a predetermined oralgorithmically-determined level or type of usage), a radio-frequencyidentification (RFID) system (e.g., RFID tag, RFID chip, etc.), or anyother component.

The control module 134 is preferably configured to implement one or moreoperation modes and/or apply one or more stimulation patterns to one ormore electrodes 112, such as through one or more stimulus generators136. The stimulation pattern preferably includes a current definition,wherein the current definition can include (or correspond to, be basedon, etc.) any or all of a current amplitude (e.g., a static currentamplitude (e.g., 1 milliampere (mA), 2 mA, less than 5 mA, etc.), amaximum current amplitude, a minimum current amplitude, etc.), a currentwaveform (e.g., sinusoidal, ramp, step, square, triangular, etc.), orany other form of current-related parameter. Additionally oralternatively, the stimulation pattern can include a voltage definition,power definition, heating command, or any other form of stimulus. Thestimulation pattern can further include temporal parameters, such as,but not limited to: a duration of a stimulus pattern (e.g., 10 minutesof constant direct current stimulation, 20 minutes of on-offstimulation, etc.), a sequence of stimulation patterns (e.g., ramp-upfollowed by static hold), time of onset (e.g., apply a specified currentdefinition at a specified time each day, upon detection of stimulationdevice placement on a user, etc.), a frequency of a current waveform,and/or a speed of propagation of a current definition. In somevariations, the temporal parameters are determined using a timingsubsystem including a set of timers. In some variations, a stimulationpattern or a set of stimulation patterns can be applied whichdynamically propagate among and/or alternate between multipleelectrodes. In one variation, each of a set of electrodes 112 can beindependently controlled by the control module 134. This can beimplemented through a separate control module 134 for each electrode, asingle control module 134 having separate ports for electrode, or anyother combination or configuration of single or multiple control modules134.

The control module 134 can operate in operation modes, each of whichpreferably includes a current definition and a temporal parameter.Additionally or alternatively, the operation modes can include an on/offstate, any form of stimulation pattern, only one of a current definitionand a temporal parameter, or any other feature of electrode stimulation.Operation modes can be assigned and/or activated by a user (e.g., usermakes selection through application on user device, sensor system ofneurostimulation device detects a user voice command, user pressesbutton on a control panel of the flexible backing, etc.), based onsensor data (e.g., pressure sensor detects when device has been placedon user), based on learned behavior of user (e.g., based on machinelearning of user preferences and patterns), based on operation context(e.g., determined based on on-board sensor signals, remote devicesignals, etc.), or based on any other input. The operation modes of thecontrol module 134 preferably at least include a first operation modecorresponding to a stimulated electrode (e.g., 1 mA direct currentapplied to electrode) and a second operation mode corresponding to anunstimulated electrode (e.g., no current applied to electrode). In oneexample of this, for instance, the first operation mode prescribes acurrent definition (e.g., pulsing direct current) and the secondoperation mode prescribes no current definition. The first operationmode of the control module 134 can further include any number ofstimulation operation modes, wherein each of the stimulation operationmodes prescribes a current definition and/or a temporal parameter. Inone variation, for instance, there can be a set of operation modes eachcorresponding to different current values/amplitudes (e.g., 1 mA, 2 mA,3 mA, etc.), different temporal parameters (e.g., current stimulationapplied constantly for 20 minutes, current stimulation applied untilturned off by a user, current stimulation pulsed for 1-ms durationsspaced 1-ms apart, etc.). Additionally or alternatively, the controlmodule can include any additional operation modes, a single operationmode, or any other operation mode.

3.10 System—Stimulus Generator.

The electronics subsystem can include a stimulus generator (e.g.,stimulus deliverer, current deliverer, current stimulus deliverer,etc.), which functions to transmit an electrical stimulus (e.g., basedon an operation mode) to one or more electrodes 112 of the electrodeassembly 110 and/or to operate in one or more operation modes.Additionally or alternatively, the stimulus generator can function toapply other stimuli, such as, but not limited to: a magnetic stimulus,ultraviolet (UV) light, heat, water, and/or any other stimuli. Thestimulus generator is preferably electrically coupled to one or moreelectrodes (e.g., to the conductive layer(s) 116, the hydrophiliclayer(s) 114, etc.), a control module 134, and a power module 142 of thesystem, but can additionally or alternatively be connected to a subsetof these (e.g., when the control module 134 is remote), connected to anyother element of the system, wirelessly connected to any element withinor outside the system, and/or mechanically connected to any element. Thestimulus generator is preferably electrically connected to the endpointsby a set of wires, but can alternatively be wirelessly connected to theendpoints or otherwise connected. The stimulus generator preferablycomprises a current generator/current stimulus deliverer (e.g., thatgenerates direct current, alternating current, both direct andalternating, etc.), but can additionally or alternatively include avoltage generator/voltage stimulus deliverer and/or any other suitablegenerator/stimulus deliverer configured to facilitate transmission of anelectrical stimulus. As such, the stimulus generator can provide one ormore current definitions, such as a direct current (DC), an alternatingcurrent (AC), an AC component superimposed on a DC component, amonophasic pulsatile waveform, a symmetrical biphasic pulsatilewaveform, an asymmetrical biphasic pulsatile waveform, and any othersuitable stimulation profile. The waveform produced by the stimulusgenerator preferably can be described by parameters comprising amplitudeand duration, but additionally or alternatively comprising any othersuitable parameter(s), such as modulation frequency, step size, meanamplitude, or root mean squared (RMS) value. Furthermore, any one ormore of the above parameters can be configured to be modulated by thestimulus generator, such that the stimulus generator can produce any oneor more of: modulated amplitudes, modulated frequencies, and modulatedpulse durations (e.g., modulated parameters characterized by exponentialdecay, exponential growth, or any other suitable growth or decayprofiles). While one stimulus generator is described, the electronicssubsystem 130 can, in some variations, comprise more than one stimulusgenerator (e.g., a separate stimulus generator for each electrode),where the control module 134 is configured to multiplex output of theadditional stimulus generators to one or more electrodes or subsectionsthereof.

3.11 System—Power Module.

The system 100 can include a power module 142, which functions to enablethe application of an electrical stimulus (e.g., current definition) toone or more electrodes of the system 100. Additionally or alternatively,the power module 142 can function to power a control module 134 and/orany other component of the system 100, provide an interface (e.g.,adapter) for the system 100 to charge externally (e.g., through a USBport), or perform any other suitable function.

The power module 142 is preferably electrically connected to the controlmodule 134 (e.g., a microprocessor), but can additionally oralternatively be electrically connected to the electrode assembly 110(e.g., the conductive substrate 116 of an electrode 112), a stimulusgenerator, and/or any other electronic component of the system 100 orexternal to the system 100 (e.g., external power source). The powermodule 142 can also be mechanically connected to any component of thesystem 100, such as mounted to an electronics housing, an electrodeassembly 110 (e.g., electrode housing 120), attached to a fasteningmeans/head apparel assembly (e.g., elastic strap), attached with a cablein the form of a pocket unit, or arranged in any other suitable way.

The power module 142 can include a power source, such as a portablepower source (e.g., battery, rechargeable battery, solar poweredbattery, etc.). Additionally or alternatively, the power module 142 caninclude one or more adapters to external power sources, such as a portor receptacle (e.g., USB port, USB-C port, USB-A port), a plug (e.g.,for a wall outlet), a cable (e.g., USB cable, extendable USB cable), aconnector/adapter configured for a vehicle power source (e.g., plug fora car cigarette lighter receptacle, connection to a vehicle USB port,etc.), and/or any other plug, adapter, or converter. Any or all of theadapters (e.g., ports, receptacles, plugs, etc.) can be located on aninner (e.g., closest to the user) broad surface of the electronicshousing 144 but can additionally or alternatively be located on asurface (e.g., an outer surface) of the electrode housing 120, oranywhere else in the system 100.

In a first variation, the power module 142 includes a rechargeablebattery and a USB port.

In a second variation, a power adapter (e.g., USB port) is arranged onthe electronics housing 144 in such a way that prevents coupling of anyor all of the electrode assembly 110 to an electronics housing 144,thereby preventing a user from applying electrical stimulation while thedevice is charging and/or connected to an external power source. In aspecific example, a charging port is arranged proximal to an electricalattachment system 150 on the electronics housing 144, such that use ofthe charging port physically interferes from coupling the electricalattachment system on the electronics housing 144 to a correspondingelectrical attachment system on the electrode housing 120.

In a third variation, the system 100 is configured for wirelesscharging. In a specific example, the electronics housing and/or anyother component of the system 100 includes an inductive coil configuredfor inductive charging (e.g., on an inductive charging pad).

In a fourth variation, the power module 142 is a pocket unit configuredto be placed in a pocket of the user. In an example, for instance, thepower module 142 is a rechargeable battery pack attached to the system100 with a cable such that the battery pack can be placed in the pocketof a user.

3.12 System—Electronics Housing.

The coupler assembly 128 preferably includes an electronics housing 144(e.g., FIGS. 5A-5C), which functions to contain one or more componentsof the electronics subsystem 130. Additionally or alternatively, theelectronics housing 144 can function to contribute flexibility to theelectronics subsystem 130, contribute structural support to the device,protect a user from the electronics subsystem 130, protect theelectronics subsystem 130 (e.g., from a user, wear-and-tear, conductivesolution, etc.), and or perform any other function.

The electronics housing 144 is preferably connected to an outer surface(e.g., broad surface furthest away from the user) of the electrodehousing 120 but can additionally or alternatively be connected to aninner surface (e.g., broad surface closest to the user) of the electrodehousing 120, partially or fully enclosed within the electrode housing120 (e.g., between an outer piece and an inner piece of the electrodehousing 120), directly connected to one or more electrodes (e.g., in theabsence of an electrode housing 120), arranged at a distance from thedevice (e.g., as a pocket unit), or arranged in any other way withrespect to any component of the device.

In some variations, the electronics housing 144 can be attached to theelectrode housing 120 through a magnetic connection. In thesevariations, the electronics housing 144 can include one or more magneticmaterials (e.g., ferromagnetic material, ferrimagnetic material,coin/disc magnet, metallic (e.g., aluminum, steel, etc.) plate, etc.)arranged in and/or on the electronics housing 144, which can reversiblycouple to one or more corresponding magnetic materials (e.g.,ferromagnetic material, ferrimagnetic material, coin/disc magnet,metallic (e.g., aluminum, steel, etc.) plate, etc.) in the electrodehousing 120. In a specific example, the electronics housing 144 includesa set of disc magnets, which reversibly couple with a steel plate of theelectrode housing 120.

The electronics housing 144 is preferably constructed with a similarprofile (e.g., contours, curvature, etc.) as the head (e.g., forehead)of a user such that it can be layered with other elements of the deviceto conform to a head of the user. Additionally or alternatively, theelectronics housing 144 can take on a number of morphologies and/orconform to various morphologies (e.g., shape memory material), have oneor more flat surfaces, or have any other suitable geometry.

The electronics housing 144 is preferably constructed from a flexiblematerial (e.g., an elastomer), such that the electronics housing 144 canconform to a variety of head sizes and shapes. Additionally oralternatively, the electronics housing 144 can be fully or partiallyrigid (e.g., rigid device constructed to conform to the head of theuser, or include a device configured with rigid regions to protect theelectronics module separated by flexible regions such as regions wherethe cross-section of the electronics housing 144 is designed with adecreased second moment to facilitate bending in a certain direction),which can function to add structural support to the device, protect theelectronics module, facilitate attachment and detachment of theelectrode assembly, or perform any other suitable function. Theelectronics housing 144 can be constructed from a polymeric material(e.g., elastomer, plastic, silicone, etc.), a foam or sponge, aconductive material (e.g., between the electronics module and theelectrode assembly), an insulative material (e.g., to protect a user),or any other material or combination of materials. The electronicshousing 144 can include any number of housing support materials (e.g.,as shown in FIG. 5C), which can function to physically support any orall of the electronics subsystem 130, retain any or all of theelectronics subsystem 130 within a volume of the electronics housing144, prevent a flexible electronics housing 144 from collapse (e.g.,under compression), guide placement of one or more components of theelectronics subsystem 130, and/or perform any other suitable function.The housing support material(s) can include any or all of rigidconnection substrates, frames, plates, blocks, and/or any other suitablecomponent. One or more housing support materials are preferablyconstructed from a relatively rigid material (e.g., polymer, plastic,metal, wood, materials having an elastic modulus above 100 MPa, above 1GPa, above 3 GPa, etc.); additionally or alternatively, one or morehousing support materials can be constructed from a relatively flexibleand/or compliant material (e.g., polymer, rubber, foam, sponge, felt,fabric, materials having an elastic modulus below 3 GPa, below 2 GPa,below 1 GPa, below 100 MPa, below 10 MPa, etc.).

Preferably, the device includes one electronics housing 144 but canadditionally or alternatively include multiple electronics housings 144(e.g., to spatially distribute the electronics module 120, to optimizeplacement of one or more components of the electronics module 120,etc.), multiple pieces to a single electronics housing (e.g., an outerelastomeric cover and an inner flexible cover), or any other number andarrangement. The electronics housing 144 can define a volume wherein theelectronics subsystem 130 is fully enclosed within the volume, partiallyenclosed within the volume, or not at all enclosed within the volume. Inone variation, the electrode housing 120 serves as at least part of theelectronics housing. In an example, for instance, the electronicshousing 130 can be arranged within a recess of the electrode housing120. The electronics housing (e.g., a backing piece) can then bearranged over the recess to enclose the electronics subsystem 130.

In one variation, the electronics housing 144 includes a flexible shellat least partially enclosing the electronics subsystem 130. In aspecific example, the flexible shell is constructed from an inner piececonnected to an outer piece. The inner and outer pieces can beconstructed from the same material or from different materials (e.g.,inner piece has higher flexibility than outer piece).

In a second variation, the electronics housing 144 is formed from partor the entirety of the electrode housing 120. In an example, forinstance, an outer (e.g., furthest from the user) surface of theelectrode housing can form an inner (e.g., closes to the user) surfaceof the electronics housing 144. In a specific example of this, theelectronics subsystem 130 can be at least partially arranged in a recessof the electrode housing 120. In another example, the electrode housing120 can contain part or all of the electronics subsystem.

3.13 System—Attachment System.

The system 100 preferably includes one or more attachment systems 150configured to connect any or all of the electrode assembly 110 to any orall of the coupler assembly 128 but can additionally or alternativelyinclude any number of attachment systems 150 to connect any element ofthe system to any other element of the system. The attachment system 150functions to electrically connect components of the system together butcan additionally or alternatively function to mechanically connectcomponents of the system together.

An attachment system 150 preferably includes a first electronic couplingassembly 151 (e.g., a set of conductive polymer contacts) arranged onthe electrode housing 120 (e.g., on an outer broad surface of theelectrode housing 120) and a second electronic coupling assembly 151(e.g., conductive polymer body including a set of conductive polymercontacts) arranged on the coupler assembly 128 (e.g., on an inner broadsurface of the electronics housing 144 adjacent the outer broad surfaceof the electrode housing 120), the first electronic coupling assemblyconfigured to be electrically connected and/or mechanically connectedthe second electronic coupling assembly 151, but one or more electroniccoupling assemblies 151 can additionally or alternatively be arrangedelsewhere in the system 100. Additionally or alternatively, anelectronic coupling assembly 151 can be arranged between an electrodeassembly and any other element of the system 100. The attachment system150 is preferably aligned in a vertical direction, such as along aninferior-superior axis when the device is placed on a user's forehead.This can function to maximize a range of flexibility of the device aboutthis axis. In a variation where the electrodes are placed to the sidesof the attachment system 150, for instance, having the attachment system150 be vertically aligned can enable a greater flexibility about theinferior-superior axis, thereby allowing the electrodes to properlyconform to a wide variety of head shapes. Additionally or alternatively,the attachment system can have no single axis of alignment, behorizontally aligned, or arranged/aligned in any other way.

The attachment system 150 (e.g., set of electronic coupling assemblies151) is preferably at least partially constructed from a conductivematerial (e.g., conductive polymer such as a conductive rubber or carbonrubber, metal, etc.) to establish an electrical connection between thecomponents. Additionally or alternatively, the attachment system 150 canbe at least partially constructed from a non-conductive (e.g.,insulative material) or any other material. In one variation, forinstance, a non-conductive material (e.g., non-conductive polymer,non-conductive elastomer, etc.) can surround a conductive material(e.g., set of conductive polymer contacts), wherein the non-conductivematerial can serve as mechanical connector (and/or an alignment tool)and the conductive material can serve as an electrical connecter. In oneexample of this, the non-conductive material includes a sealingmechanism (e.g., a face seal gasket). In another specific example, aface seal gasket separates the conductive material from thenon-conductive material. In some variations, the material(s) of theattachment system can be flexible (e.g., rubber, elastomer, etc.) and/orcompliant (e.g., rubber, foam, sponge, etc.) for comfort, conforming toa user's head, etc. In other variations, the material(s) of theattachment system can be rigid (e.g., metallic, magnetic, polymeric,wood, etc.) to contribute structural support or for any other purpose.

The attachment system 150 preferably includes a set of terminalsarranged in one or more electronic coupling assemblies 151, wherein eachof the terminals is electrically connected to a single electrode 112.Additionally or alternatively, the attachment system can include asingle terminal connected to one or more electrodes, multiple terminalsconnected to a single electrode, or any number and arrangement ofterminals and electrodes. In some variations, the set of terminalsincludes one or more gaskets (e.g., face seal gaskets), which canfunction to fluidly seal the attachment system 150 from a fluid (e.g.,conductive solution), to isolate a terminal from one or more otherterminals, or for any other purpose.

In some variations, the attachment system 150 includes a firstelectronic coupling assembly 151 connected to the electrode assembly 110and a second electronic coupling assembly 151 connected to theelectronics housing 144, wherein the first and second electroniccoupling assemblies 151 are removably couplable to each other. In othervariations, the first and second attachment pieces can be permanentlycoupled to each other.

In some variations, the attachment system 150 includes one or moremechanical attachment systems. The mechanical attachment system can beintegrated into an electrical attachment system or be separate. Themechanical attachment system 150 can function to connect the electrodehousing 120 to the electronics housing 144, the electrode assembly 110to the electronics subsystem 130, and/or to connect any other componentsof the system 100. The mechanical attachment system can include a set ofattractive (e.g., opposing polarity) magnetic components (e.g., discmagnets, steel plates, etc.), a set of contacts (e.g., male attachmentpiece) which fit into a set of receptacles (e.g., female attachmentpiece), a hook-and-loop fastener (e.g., Velcro) system, adhesive, ties,or any other mechanical attachment component. In one example, theelectronics housing 144 includes a set of magnets (e.g., disc magnets),which form a mechanical connection with a steel plate in the electrodehousing 120.

The attachment system 150 can further include any number of attachmentsupport materials, which can function to structurally support theattachment system 150, such as in the implementation of an attachmentsystem 150 in a flexible/compliant structure (e.g., flexible electronicshousing). This can include one or more rigid connection blocks, plates,rods, etc. In one variation, as shown in FIG. 7C, the attachment system150 can include a set of connection blocks (e.g., an inner connectionblock and an outer connection block) proximal one or more othercomponents of the attachment system 150, such as a magnetic mechanicalattachment system 150. In some variations, the attachment supportmaterials can include any or all of the housing support materials.

In one variation, one or more electronic coupling assemblies 151 of theattachment system 150 includes one or more conductive polymer (e.g.,conductive rubber such as carbon rubber) bodies. In a specific example,an electronic coupling assembly including a conductive polymer body isexposed through an opening of the electronics housing 144, wherein theconductive polymer body can include a set of conductive polymer contacts(e.g., as shown in FIGS. 6A-6B) which couple with an electronic couplingassembly 151 including a complementary set of conductive polymercontacts (e.g., conductive polymer receptacles on an outer surface ofthe electrode housing 120, as shown in FIGS. 7D-7E). In another specificexample, the electronic coupling assembly 151 of the electrode assembly120 includes a set of conductive polymer contacts which are couplable toa complementary set of conductive polymer contacts (e.g., conductivepolymer receptacles) of an electronic coupling assembly 151 of theelectronics housing 144. Preferably the complementary sets of conductivepolymer contacts are vertically aligned (e.g., FIGS. 6A-6B and 7D-7E)but can additionally be arranged in any other way. The conductivepolymer contacts can be arranged with a fixed spacing, a variablespacing, or any other spacing. In one example, a set conductive polymercontacts are evenly spaced. In another example, the spacing between afirst and second conductive polymer contact is smaller than the spacingbetween a second and third conductive polymer contact. The attachmentsystem can include any number of contacts/receptacles (e.g., one perelectrode, one per electrode plus an additional contact, etc.). Thisvariation can further include one or more sealing mechanisms arrangedbetween complementary rubber contacts to prevent fluid ingress into avolume (e.g., cavity, barrel, etc.) of an electronic coupling assembly151 and/or between electronic coupling assemblies 151.

In another variation, the attachment system includes a conductivepolymer (e.g., carbon rubber) attachment system along with a mechanicalattachment system (e.g., magnetic attachment system).

In yet another variation, the attachment system includes a firstelectronic coupling assembly 151 having a set of non-polymeric (e.g.,metallic) contacts which are couplable with a second electronic couplingassembly 151 having a set of non-polymeric (e.g., metallic) receptacles.Additionally or alternatively, one electronic coupling assembly 151having a conductive polymeric material (e.g., conductive rubber) can becoupled to an electronic coupling assembly 151 having a conductivenon-polymeric material (e.g., metal).

3.14 System—Sealing Structures.

The system 100 preferably includes one or more sealing structures,wherein a sealing structure can function to obstruct liquid (e.g.,conductive gel or liquid, user perspiration, spills, rain, water fromwashing, etc.) access to the electronics subsystem (e.g., during use).The sealing structure can include any or all of a sealing component(e.g., gasket, O-ring, stopper, etc.) and/or an interface betweencomponents (e.g., adhesive interface, laminated interface, interlockinginterface, press-fit interface, etc.) formed by any form of manufactureand/or assembly (e.g., lamination, injection molding, co-molding,press-fitting, etc.). Preferably, an attachment system 150 between theelectrode assembly 110 and the electronics subsystem 130 includes asealing structure; additionally or alternatively, a sealing structure(e.g., face-seal gasket arranged on the perimeter of one or moreelectrodes 112) is arranged between one or more electrodes 112 and therest of the electrode assembly 110, between an attachment system 150 andthe electronics subsystem 130, between the electronics housing 144 andany other element of the electronics subsystem 130, and/or between anyother elements of the system 100.

In one variation, two or more elements of the system 100 collectivelydefine the sealing structure. In a specific example, for instance, theattachment system 150 (e.g., conductive polymer body of the electronicssubsystem 130 and electronic coupling assembly of the electrode assembly110) and the electronics housing 144 collectively define a sealingstructure.

In a second variation (e.g., as shown in FIG. 7A), the sealing structureis formed from one or more face seal gaskets incorporated with (e.g.,surrounding) an electrical attachment system 150. The one or more faceseal gaskets are preferably constructed from an elastomeric material butcan additionally or alternatively be constructed from any polymericmaterial and/or any other material. The one or more face seal gasketsare preferably constructed from a non-conductive material (e.g.,non-conductive elastomer) but can additionally or alternatively beconstructed from a conductive material. In a specific example, a faceseal gasket surrounds a set of conductive polymer contacts. In aspecific example (e.g., as shown in FIG. 6B), a face seal gasketsurrounds each of a set of contacts (e.g., the set of conductive polymercontacts arranged on the coupler assembly, the set of conductive polymercontacts arranged on the electrode assembly, both sets of conductivepolymer contacts, etc.). In yet another specific example, a first faceseal gasket can be arranged around a set of conductive polymer contacts(e.g., conductive rubber contacts) and an additional set of face sealgaskets can be arranged around each of a set of conductive polymercontacts.

In a third variation, one or more conductive polymer contacts isconstructed with a feature to prevent fluid ingress. In a first specificexample, one or more conductive polymer contacts are configured to bepress fit together to prevent fluid ingress. In a second specificexample, one or more conductive polymer contacts includes a surfacetexture for a sealed fit when mated with another conductive polymercontact. In a third specific example, one or more conductive polymercontacts include a gasket, rim, and/or other features for establishing aseal when mated with another element (e.g., complementary conductivepolymer contact) of the electronic coupling assembly 151.

3.15 System—Head Apparel Assembly.

The system 100 preferably includes a head apparel assembly 170, whichfunctions to secure the system 100 (e.g., a cosmetic outer element 160,one or more electrodes 112, etc.) to a head region (e.g., forehead) ofthe user. Additionally or alternatively, the system 100 can be securedto a head region of the user using an adhesive, a sticky conductivesolution, through gravity, using an external head apparel assembly(e.g., a hat of a user), or using any other element.

The head apparel assembly 170 is preferably adjustable and/or elastic inorder to fit a variety of user head morphologies but can alternativelybe a single size. The head apparel assembly 170 can include a compliantmaterial (e.g., foam helmet), a flexible material (e.g., an elasticstrap), a rigid material (e.g., a polymer frame, glasses frame/glassesarms, headphone/headset frame, etc.), a fabric material (e.g., polyesterband, hat, etc.), any other material or any combination of materials.The head apparel assembly 170 can include any or all of: a strap (e.g.,elastic strap), helmet (e.g., foam helmet, biking helmet, footballhelmet, etc.), frame (e.g., glasses frame, headphone/headset frame,polymer frame, etc.), headband (e.g., sweatband), hat (e.g., baseballcap, beanie, etc.), and/or any other element.

The head apparel assembly can be connected to the electrode assembly110, the electronics subsystem 130, any other element of the system 100,held to a user's head through compression, or not attached at all. Thehead apparel assembly can be attached to the rest of the system 100 withany type and number of fasteners, such as screws, press-fit components(e.g., press-fit bollards), adhesive, hook-and-loop fasteners, ties,buttons, snaps, straps, buckles (e.g., watch strap buckle), clamps,and/or any other suitable fastening mechanism.

3.16 System—Cosmetic Outer Element.

In some variations, the head apparel assembly 170 includes a cosmeticouter element 160 (e.g., FIGS. 4A-4E), which functions to contributestructural stability to the system 100 and/or provide an attractivecosmetic appearance to the system 100. Additionally or alternatively,the cosmetic outer element 160 can function to retain the system 100 tothe head of a user, hold the system 100 in place in a predeterminedlocation (e.g., proximal a set electrode placement regions), protect anypart of the system 100 (e.g., the electronics subsystem) from theenvironment and/or wear-and-tear, and/or perform any other suitablefunction.

The cosmetic outer element 160 is preferably connected to one or moreother components of the head apparel assembly 170 (e.g., elastic strap,hat, headset, headphones, flexible frame arranged circumferentiallyaround the user), such that the cosmetic outer element 160 is retainedat a desired location on the head (e.g., over the forehead region) of auser. Additionally or alternatively, the cosmetic outer element 160 canbe secured to the head of a user (e.g., with an adhesive) withoutadditional components of the head apparel assembly 170, held withcompression, held at a distance (e.g., with a frame), or otherwisearranged proximal the head of a user. The cosmetic outer element 160 ispreferably arranged further away from the user (e.g., more external thananother element of the system 100, etc.) than the electrode assembly110, but can additionally or alternatively be arranged partiallyexternal the electrode assembly 110, partially or fully external theelectronics subsystem 130, or arranged in any other way with respect tothe system 100.

The cosmetic outer element 160 is preferably constructed with a similarshape (e.g., curvature, set of contours, depth, profile, etc.) as one ormore components of the system 100 arranged closer to the user than(e.g., internal) the cosmetic outer element 160, such that the cosmeticouter element 160 can be stacked on/layered over the inner component(s).Additionally or alternatively, part or all of the cosmetic outer element160 can be constructed with a similar shape (e.g., curvature, set ofcontours, depth, profile, etc.) as that of a head region (e.g.,forehead, neck) of the user, to facilitate and maintain proper placementof any or all of the system 100 on a user. Further additionally oralternatively, the cosmetic outer element 160 can be compliant and/orflexible enough to take on a wide range of shapes, can be constructedwith a different shape than any other component of theelectrostimulation device, or can be constructed to have any othersuitable geometry.

A broad surface (e.g., outer surface, inner surface) of the cosmeticouter element 160 can generally be the same size (e.g., average sizeamong a sample of users, largest size in a sample of users, etc.) as aforehead region, one or more electrode regions, a brain/scalp region,any other region of the user, or can be any suitable size.

The cosmetic outer element 160 is preferably constructed from one ormore comfort materials, such as, but not limited to: relativelycompliant materials (e.g., elastic modulus less than 100 MPa) and/orrelatively flexible materials (e.g., spring constant less than 200 N/m,less than 100 N/m, less than 50 N/m, less than 30 N/m, between 20 and 80N/m, etc.) in order to contour/conform to a variety of user headmorphologies, but can additionally or alternatively be constructed fromone or more support materials (e.g., rigid materials, materials havingan elastic modulus above 100 MPa, above 1 GPa, above 3 GPa, etc.), acombination of comfort and support materials, or any other material orcombination of materials. The cosmetic outer element 160 is preferablyinsulative (e.g., to protect a user), but can additionally oralternatively be conductive. In some variations, the cosmetic outerelement 160 is hydrophobic, such that the cosmetic outer element doesnot absorb liquids (e.g., from user perspiration, from the environment,from a conductive solution, etc.), but can additionally or alternativelybe hydrophobic.

In preferred variations, the cosmetic outer element 160 includes one ormore cosmetic support materials, such as a frame, plate, lattice, beam,or any other component which functions to support (e.g., maintain) thestructure of the cosmetic outer element 160. The cosmetic supportmaterial(s) can be constructed from a polymer, metal, rigid foam orsponge, or any other material(s). The cosmetic outer element 160 canfurther include one or more compliant and/or flexible materials, such asa foam pad, polymeric plate, felt pad, sponge layer, fabric, or anyother material. In some variations, a compliant material is arrangedclosest to the user for comfort and a rigid material is arrangedexternal to the compliant material for protection of the system 100. Thecompliant material(s) can be constructed from a foam or sponge, fabric(e.g., felt, polyester, cotton, etc.), polymer (e.g., silicone, rubber,etc.) or any other material(s). The support material(s) and thecompliant/flexible material(s) can be layered (e.g., in an alternatingfashion), partially or fully surrounded by (e.g., wrapped in) a fabricbacking, and/or arranged in any other way.

There is preferably one cosmetic outer element 160 for each head apparelassembly 170, but the head apparel assembly 170 can additionally oralternatively include multiple cosmetic outer elements 160 (e.g., oneper electrode, multiple per electrode, etc.) or no cosmetic outerelement 160.

The cosmetic outer element 160 preferably includes one or moreattachment sites for one or more other components (e.g., strap, frame,etc.) of the head apparel assembly 170. The attachment site(s) caninclude any or all of: one or more cutout regions (e.g., to attach theends of a strap), recesses or grooves (e.g., to retain and/or guideplacement of a strap), hinges (e.g., to attach arms of glasses), hooks,clasps, hook-and-loop fasteners (e.g., Velcro), adhesives, clamps, orany other type of fastener or means for attachment. Additionally oralternatively, the cosmetic outer element 160 can serve as the headapparel assembly (e.g., wrap circumferentially around the head of auser).

In a first variation, the cosmetic outer element 160 is arrangedexternal to the electrode assembly 110 and the electronics subsystem130. In a first specific example, the cosmetic outer element 160,electrode housing 120, and electronics housing 144 are all constructedto have a size and curvature similar to those of a user's foreheadregion, such that the components can be stacked/layered over each otherand secured to the user's forehead. The cosmetic outer element 160 inthis specific example can further include an external and/or an internalfabric layer, which can function to add comfort to the device, concealone or more materials (e.g., rigid frame of the cosmetic outer element)of the device, and/or contribute to the aesthetic qualities of thedevice.

In a second variation, the cosmetic outer element can function toconnect one or more electrodes 112 to a head apparel assembly. In aspecific example, as shown in FIG. 10, the cosmetic outer element 160can include multiple pieces, each arranged on a broad outer surface ofan electrode.

In a third variation (e.g., as shown in FIGS. 10-12) the head apparelassembly 170 includes a cosmetic outer element 160 connected to a framearranged at least partially circumferentially around the head of a user.In a first specific example, the cosmetic outer element 160 is connectedto a pair of glasses arms, the glasses arms resting on a user's ears,wherein the glasses arms function to couple the cosmetic outer 160 to auser's head (e.g., forehead region).

In a fourth variation, the cosmetic outer element 160 has a layeredstructure including a curved plate (e.g., plastic plate) arrangedexternally (e.g., further from the user) and a foam pad arrangedinternal (e.g., closer to the user) to the curved plate. In a specificexample, the cosmetic outer element 160 is wrapped in a fabric layer.Any or all of the cosmetic outer element 160 layers can be securedtogether through a lamination process, using adhesive, press-fitbollards, screws, a snap ring, or in any other way with any suitablecomponent of the system 100.

In a fifth variation, the system 100 is in the form of a headband,wherein the head apparel assembly includes an elastic strap. In a firstexample, the strap is connected to a cosmetic outer element 160, whereinthe cosmetic outer element 160 is placed on the forehead of a user andthe strap is arranged around the back of the user's neck or head. In asecond example, the strap runs circumferentially around the head of auser and can be arranged external to the system 100, within a recess ofthe cosmetic outer 160, between a cosmetic outer 160 and an electronicssubsystem 130, between an electronics subsystem 130 and an electrodeassembly 120, or arranged in any other way.

In a sixth variation (e.g., as shown in FIG. 13), the system 100 is inthe form of a hat insert, wherein the head apparel assembly 170 includesa hat. In a specific example, the hydrophilic layer 114 of one or moreelectrodes 112 includes a set of ridges to part through a user's hair inorder to establish contact between the electrode 112 and the user'sscalp. In another specific example the system 100 can include anattachment system 150 (e.g., hook, Velcro, adhesive, etc.) to connectthe system 100 to the hat. In a third variation, the system 100 issimply held by compressive forces from the hat.

In a seventh variation (e.g., as shown in FIGS. 10-12), the system 100is in the form of a frame, wherein the frame at least partiallycircumferentially wraps around the head of the user to secure the system100 to the user's head. In a first specific example (e.g., as shown inFIG. 12), the frame includes a glasses frame (e.g., set of rigid glassesarms). In a second specific example, the frame is bendable such that theuser can adjust the configuration of the frame to fit the user andtarget a desired set of stimulation regions. In a third variation, theframe is rigid (e.g., constructed based on a set of user headmeasurements). In a fourth variation, the frame is elastic to deformelastically to accommodate head size and shape variation.

Although omitted for conciseness, the preferred embodiments includeevery combination and permutation of the various system components.

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the preferred embodiments of the invention withoutdeparting from the scope of this invention defined in the followingclaims.

We claim:
 1. An electrode assembly for electrically stimulating a user,the electrode assembly comprising: a set of electrodes each comprising:a hydrophilic foam; a support structure retaining the hydrophilic foam;a conductive polymer substrate in electrical communication with thehydrophilic foam; and an electrical coupler; a compliant base configuredto conform to a curvature of a forehead-region of the user during use,the compliant base retaining each of the set of electrodes in positionand separating each of the set of electrodes from each other; and anelectronic coupling assembly coupled to the electrical coupler of eachof the set of electrodes through the compliant base and configured tocouple the set of electrodes to an electronics subsystem.
 2. Theelectrode assembly of claim 1, wherein at least one of the set ofelectrodes comprises a backing foam.
 3. The electrode assembly of claim2, wherein the backing foam is arranged between the hydrophilic foam andthe conductive polymer.
 4. The electrode assembly of claim 1, wherein afirst of the set of electrodes is arranged proximal to a righthemispheric brain region and wherein a second of the set of electrodesis arranged proximal to a left hemispheric brain region.
 5. Theelectrode assembly of claim 4, wherein the right hemispheric brainregion comprises a right supraorbital region and wherein the lefthemispheric brain region comprises an F3 region of electrode placement.6. The electrode assembly of claim 4, wherein an angle between a firsttangent plane and a second tangent plane, the first tangent planetangent to a first center point of an inner broad surface of a first ofthe set of electrodes and the second tangent plane tangent to a secondcenter point of an inner broad surface of a second of the set ofelectrodes, has a value between 8.5 and 18.5 degrees.
 7. The electrodeassembly of claim 6, wherein a vertical spacing between a first centerof an inner broad surface of the first of the set of electrodes and asecond center of an inner broad surface of the second of the set ofelectrodes, the vertical spacing defined along an inferior-superioraxis, is between twenty-five and fifty-five millimeters, and wherein ahorizontal spacing between the first center and the second center, thehorizontal spacing defined along a medial-lateral axis perpendicular tothe inferior-superior axis, is between sixty-nine and ninety-ninemillimeters.
 8. The electrode assembly of claim 1, wherein theelectronic coupling assembly further comprises a first set of conductivepolymer contacts, the first set of conductive polymer contactselectrically connected to a second set of conductive polymer contacts onthe electronics subsystem.
 9. The electrode assembly of claim 8, whereinthe first and second sets of conductive polymer contacts are verticallyaligned along an inferior-superior axis.
 10. The electrode assembly ofclaim 1, wherein the compliant base comprises a hydrophobic material.11. The electrode assembly of claim 10, wherein the hydrophilic foam ofeach of the set of electrodes comprises a salt integrated into thehydrophilic foam.
 12. An electrode assembly for electrically stimulatinga user, the electrode assembly comprising: a set of electrodes eachcomprising: a hydrophilic foam; a support structure retaining thehydrophilic foam; a conductive polymer substrate in electricalcommunication with the hydrophilic foam; and an electrical coupler; acompliant base comprising a first base portion and a second baseportion, the first and second base portions coupled together, thecompliant base configured to conform a curvature of a forehead-region ofthe user during use, the compliant base separating each of the set ofelectrodes from each other and retaining the set of electrodes in a setof positions, wherein a first of the set of positions is proximal to anF3 electrode region and a second of the set of positions is proximal toa right supraorbital region; and an electronic coupling assembly coupledto the electrical coupler of each of the set of electrodes through thecompliant base and configured to couple the set of electrodes to anelectronics subsystem, the electronic coupling assembly comprising asealing connection.
 13. The electrode assembly of claim 12, wherein atleast one of the set of electrodes comprises a backing foam.
 14. Theelectrode assembly of claim 13, wherein the backing foam is arrangedbetween the hydrophilic foam and the conductive polymer substrate. 15.The electrode assembly of claim 12, wherein an angle between a firsttangent plane and a second tangent plane, the first tangent planetangent to a first center point of an inner broad surface of a first ofthe set of electrodes and the second tangent plane tangent to a secondcenter point of an inner broad surface of a second of the set ofelectrodes, has a value between 8.5 and 18.5 degrees.
 16. The electrodeassembly of claim 15, wherein a vertical spacing between a first centerof an inner broad surface of the first of the set of electrodes and asecond center of an inner broad surface of the second of the set ofelectrodes, the vertical spacing defined along an inferior-superioraxis, is between twenty-five and fifty-five millimeters, and wherein ahorizontal spacing between the first center and the second center, thehorizontal spacing defined along a medial-lateral axis perpendicular tothe inferior-superior axis, is between sixty-nine and ninety-ninemillimeters.
 17. The electrode assembly of claim 12, wherein theelectronic coupling assembly further comprises a first set of conductivepolymer contacts, the first set of conductive polymer contactselectrically connected to a second set of conductive polymer contacts onthe electronics subsystem.
 18. The electrode assembly of claim 17,wherein the first and second sets of conductive polymer contacts arevertically aligned along an inferior-superior axis.
 19. The electrodeassembly of claim 12, wherein the compliant base comprises a hydrophobicmaterial.
 20. The electrode assembly of claim 19, wherein thehydrophilic foam of each of the set of electrodes comprises a saltintegrated into the hydrophilic foam.